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Ding S, Zhang S, Wang Y, Chen S, Chen Q. Restricted colloidal-bound phosphorus release controlled by alternating flooding and drying cycles in an alkaline calcareous soil. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 343:123204. [PMID: 38142807 DOI: 10.1016/j.envpol.2023.123204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 12/11/2023] [Accepted: 12/20/2023] [Indexed: 12/26/2023]
Abstract
Colloid-facilitated phosphorus (P) migration plays an important role in P loss from farmland to adjacent water bodies. However, the dynamics of colloidal P (Pcoll) release as influenced by irrigation in alkaline calcareous soil remains a knowledge gap. The present study, monitored the dynamic change of Pcoll under different water management strategies: 1) control, 2) flooding, and 3) alternating flooding and drying cycles. Soil water-dispersible colloids (0.6 nm-1 μm) were extracted by combining filtration and ultrafiltration methods. The contents of P, cation and organic carbon in the water-dispersible colloids were determined and the stability and mineral composition of colloidal fractions were characterized. The results showed that Pcoll ranged from 16.5 to 25.5 mg kg-1 and represented 42.8%-64.9% of the water-extracted P in the control. Flooding significantly decreased the Pcoll content by 16.0%-62.1% (mean 32.7%) and it may be attributed to the dissolution of colloidal iron (Fe) bound P. The alternating flooding and drying treatment significantly reduced the Pcoll content by 11.6%-88.0% (mean 67.6%). The Pcoll content of the flooding event was always greater than the Pcoll content of the drying event during flooding and drying cycles. Redundancy analysis and random forest modeling showed that the colloidal calcium (Ca) and ionic strength in soil solutions had negative correlations with the Pcoll content, and pH, ionic strength and truly dissolved P were the critical factors affecting Pcoll. Drying of the flooded soil led to the decrease of pH and the increase of ionic strength, colloidal Ca content and positive charges of colloid surfaces, which promoted colloid aggregation and enhanced soil P sorption capacity. This restricted the loss potential of Pcoll. In summary, controlled flooding and drainage when managed correctly have a role to play in mitigating Pcoll loss from P-enriched calcareous soils.
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Affiliation(s)
- Shuai Ding
- Beijing Key Laboratory of Farmland Soil Pollution Prevention-control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian, Beijing, 100193, PR China
| | - Shuai Zhang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention-control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian, Beijing, 100193, PR China; Key Laboratory of Arable Land Quality Monitoring and Evaluation, State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, PR China.
| | - Yang Wang
- College of Land Science and Technology, China Agricultural University, Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture, Beijing, 100193, PR China
| | - Shuo Chen
- Beijing Key Laboratory of Farmland Soil Pollution Prevention-control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian, Beijing, 100193, PR China
| | - Qing Chen
- Beijing Key Laboratory of Farmland Soil Pollution Prevention-control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian, Beijing, 100193, PR China
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Wu S, Zhang Z, Sun H, Hu H. Responses of Rice Yield, N Uptake, NH 3 and N 2O Losses from Reclaimed Saline Soils to Varied N Inputs. PLANTS (BASEL, SWITZERLAND) 2023; 12:2446. [PMID: 37447008 PMCID: PMC10347052 DOI: 10.3390/plants12132446] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 06/20/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023]
Abstract
It is of agronomic importance to apply nitrogen (N), but it has high environmental risks in reclaimed saline soils. Therefore, we should apply N fertilizer at an appropriate rate to increase crop yield but decrease N losses. In this soil column experiment, rice yield, N uptake, and ammonia (NH3) and nitrous oxide (N2O) losses were measured in four treatments with no N application (control) and with N applications of 160, 200, and 240 kg/ha (N160, N200, and N240, respectively). The results show that grain yield, spike number, and thousand-kernel weight increased with increases in N application rate, but there was no significant difference in grain yield between N200 and N240. However, the kernels per spike increased first and then decreased with the increase in N application, of which N200 was recorded to have the highest kernels per spike value, which was 16.8 and 9.8% higher than those of N160 and N240, respectively. Total NH3 volatilization of the rice season increased with increasing N input, especially during the first and second supplementary fertilization stages. The NH4+-N concentration of overlying water was relatively lower under the N200 treatment in these two stages, and the yield-scaled NH3 volatilization and the emission factor were the lowest in N200, which were 26.2-27.8% and 4.0-21.0% lower than those of N160 and N240, respectively. Among the three N-applied treatments, N2O losses and the emission factor as well as the yield-scaled N2O emissions were the lowest under the N200 treatment, which had 34.7% and 78.9% lower N2O emissions and 57.8% and 83.5% lower emission factors than those of the N160 and N240 treatments, respectively. Moreover, the gene copies of AOA and AOB amoA, nirS, and nirK in cultivated layer soils all reached the minimum under the N200 treatment. According to the comprehensive effects of N fertilizer on rice grain yield and NH3 and N2O losses, we recommend applying 200 kg/ha to reclaimed saline soil to ensure crop yield and reduce N losses.
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Affiliation(s)
- Si Wu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China; (S.W.); (H.H.)
| | - Zhenhua Zhang
- Jiangsu Key Laboratory for Bioresource of Saline Soils, School of Wetlands, Yancheng Teachers University, Yancheng 224007, China;
- School of Agriculture and Environment, The University of Western Australia, Crawley, WA 6009, Australia
| | - Haijun Sun
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China; (S.W.); (H.H.)
| | - Haibo Hu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China; (S.W.); (H.H.)
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Tang S, Rao Y, Huang S, Xu Y, Zeng K, Liang X, Ling Q, Liu K, Ma J, Yu F, Li Y. Impact of environmental factors on the ammonia-oxidizing and denitrifying microbial community and functional genes along soil profiles from different ecologically degraded areas in the Siding mine. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 326:116641. [PMID: 36343494 DOI: 10.1016/j.jenvman.2022.116641] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 10/08/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Ammonia oxidizers (ammonia-oxidizing bacteria (AOB amoA) and ammonia-oxidizing archaea (AOA amoA)) and denitrifiers (encoded by nirS, nirK and nosZ) in the soil nitrogen cycle exist in a variety of natural ecosystems. However, little is known about the contribution of these five N-related functional genes to nitrification and denitrification in the soil profile in severely ecologically degraded areas. Therefore, in the present study, the abundance, diversity and community composition of AOA, AOB, nirS, nirK and nosZ were investigated in the soil profiles of different ecologically degraded areas in the Siding mine. The results indicated that, at the phylum level, the dominant archaea were Crenarchaeota and Thaumarchaeota and the dominant bacteria were Proteobacteria. Heavy metal contents had a great impact on AOA amoA, nirS and nirK gene abundances. AOA amoA contributed more during the ammonia oxidation process and was better adapted for survival in heavy metal-contaminated environments. In addition to heavy metals, the soil organic matter (SOM) content and C/N ratio had strong effects on the AOA and AOB community diversity and structure. In addition, variations in the net ammonification and nitrification rates were proportional to AOA amoA abundance along the soil profile. The soil C/N ratio, soil available phosphorus content and soil moisture influenced the denitrification process. Both soil available phosphorus and moisture were more strongly related to nosZ than to nirS and nirK. In addition, nosZ presented a higher correlation with the nosZ/(nirS + nirK) ratio. Moreover, nosZ/(nirS + nirK) was the key functional gene group that drove the major processes for NH4+-N and NO3--N transformation. This study demonstrated the role and importance of soil property impacts on N-related microbes in the soil profile and provided a better understanding of the role and importance of N-related functional genes and their contribution to soil nitrification and denitrification processes in highly degraded areas in the Siding mine.
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Affiliation(s)
- Shuting Tang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Yin Rao
- College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Shulian Huang
- College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Yue Xu
- College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Kaiyue Zeng
- College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Xin Liang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Qiujie Ling
- College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Kehui Liu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, 541004, Guilin, China; College of Life Science, Guangxi Normal University, 541004, Guilin, China
| | - Jiangming Ma
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, 541004, Guilin, China; College of Life Science, Guangxi Normal University, 541004, Guilin, China
| | - Fangming Yu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, 541004, Guilin, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China.
| | - Yi Li
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, 541004, Guilin, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China.
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Ni B, Xu X, Zhang W, Yang X, Liu R, Wang L, Wu W, Meng F. Reduced fertilization mitigates N 2O emission and drip irrigation has no impact on N 2O and NO emissions in plastic-shed vegetable production in northern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 824:153976. [PMID: 35181370 DOI: 10.1016/j.scitotenv.2022.153976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 02/09/2022] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
Plastic-shed vegetable production in China creates hotspots for emission of the potent greenhouse gas nitrous oxide (N2O) and the atmospheric pollutant nitric oxide (NO). To mitigate N2O and NO emissions, determination of the predominant processes of N2O and NO generation in plastic-shed vegetable production is important. Here, we reported the findings of a 2-year experimental study on the effects of reduced fertilization and/or drip irrigation on N2O and NO emissions during plastic-shed tomato production in northern China. Five treatments were applied: 1) over fertilization and flood irrigation (conventional practice); 2) fertilization reduced by 20% and flood irrigation; 3) fertilization reduced by 20% and drip irrigation; 4) fertilization reduced by 30% and drip irrigation, and 5) control (no fertilizer input and flood irrigation). Reduced both basal and top-dressed fertilization maintained tomato yields. Compared with conventional practices (mean annual N2O and NO emissions: 18.1 ± 1.3 and 0.79 ± 0.02 kg N ha-1 yr -1, respectively), fertilization reduction by 20%-30% decreased the annual N2O emission by 21.2%-27.0% owing to lower soil inorganic nitrogen (SIN) contents under the reduced fertilization practices. Switching from flood to drip irrigation might weaken denitrification due to lower soil moisture and less wet soil area, but increased SIN contents, and thus had no significant impact on annual N2O and NO emissions. Peak N2O fluxes occurred at soil temperature 28 °C and water-filled pore space (WFPS) > 60%, were higher than those for NO, and peak NO fluxes appeared 4-6 days later than N2O fluxes, consistent with the decline in WFPS. These observations indicated that N2O and NO from alkaline plastic-shed soil may be mainly generated via heterotrophic denitrification and nitrification, respectively. Reduced fertilization and drip irrigation in plastic-shed tomato production maintained crop productivity and mitigated N2O emission. These results could be integrated into the decision-making in sustainable plastic-shed production.
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Affiliation(s)
- Bang Ni
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Xiuchun Xu
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Wei Zhang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Xuan Yang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Rui Liu
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Ligang Wang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Key Laboratory of Agricultural Non-point Source Pollution Control, Ministry of Agriculture, Beijing 100081, China
| | - Wenliang Wu
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Fanqiao Meng
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
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5
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Nikolenko O, Brouyѐre S, Goderniaux P, Robert T, Orban P, Borges AV, Jurado A, Duvivier M, Morana C. Dynamics of nitrous oxide with depth in groundwater: Insights from ambient groundwater and laboratory incubation experiments (Hesbaye chalk aquifer, Belgium). JOURNAL OF CONTAMINANT HYDROLOGY 2021; 241:103797. [PMID: 33813144 DOI: 10.1016/j.jconhyd.2021.103797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 02/27/2021] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Aquifers under agricultural areas are considered to be an indirect source of nitrous oxide emission (N2O) to the atmosphere, which is the greenhouse gas (GHGs) characterized with the highest global warning potential and acts as a stratospheric ozone depletion agent. Previous investigations performed in the Cretaceous Hesbaye chalk aquifer in Eastern Belgium suggested that the dynamics of N2O in the aquifer is controlled by overlapping biochemical processes such as nitrification and denitrification. The current study aims to obtain better insight concerning the factors controlling the distribution of N2O concentration along a vertical dimension in the aquifer, and to capture and quantify the occurrence of nitrification and denitrification processes in the groundwater system. Low-flow groundwater sampling technique was undertaken at different depths in the aquifer to collect groundwater samples aiming at obtaining information about ambient aquifer hydrogeochemical conditions and their effect on the accumulation of GHGs. Afterwards, laboratory stable isotope experiments, using NO3- and NH4+ compounds labeled with heavy 15N isotope, were applied to quantify the rates of nitrification and denitrification processes. Ambient studies suggest that the occurrence of N transformation was related to denitrification while laboratory incubation experiments did not detect it. Such controversial results might be explained by the discrepancy between real aquifer conditions and lab design studies. Thus, additional in situ tracer experiments should be carried out in areas where natural groundwater fluxes do not flush the injected tracer too rapidly. In addition, it would be useful to conduct microbiological studies to obtain better insight into the nature of subsurface biofilm biotope.
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Affiliation(s)
- Olha Nikolenko
- University of Liѐge, Urban and Environmental Engineering Department, Hydrogeology and Environmental Geology, Aquapôle, 4000 Liѐge, Belgium
| | - Serge Brouyѐre
- University of Liѐge, Urban and Environmental Engineering Department, Hydrogeology and Environmental Geology, Aquapôle, 4000 Liѐge, Belgium.
| | - Pascal Goderniaux
- Geology and Applied Geology, Polytech Mons, University of Mons, Mons, Belgium
| | - Tanguy Robert
- University of Liѐge, Urban and Environmental Engineering Department, Hydrogeology and Environmental Geology, Aquapôle, 4000 Liѐge, Belgium; F.R.S.-FNRS (Fonds de la Recherche Scientifique), 1000 Brussels, Belgium; VIVAQUA, Direction de la Production, Hydrogéologie, 1000 Brussels, Belgium
| | - Philippe Orban
- University of Liѐge, Urban and Environmental Engineering Department, Hydrogeology and Environmental Geology, Aquapôle, 4000 Liѐge, Belgium
| | | | - Anna Jurado
- GHS, Institute of Environmental Assessment and Water Research (IDAEA), Severo Ochoa Excellence Center of the Spanish Council for Scientific Research (CSIC), Barcelona, Spain
| | - Maxime Duvivier
- University of Liѐge, Urban and Environmental Engineering Department, Hydrogeology and Environmental Geology, Aquapôle, 4000 Liѐge, Belgium
| | - Cedric Morana
- Chemical Oceanography Unit, University of Liѐge, Liѐge, Belgium
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Zhong C, Liu Y, Xu X, Yang B, Aamer M, Zhang P, Huang G. Paddy-upland rotation with Chinese milk vetch incorporation reduced the global warming potential and greenhouse gas emissions intensity of double rice cropping system. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 276:116696. [PMID: 33744496 DOI: 10.1016/j.envpol.2021.116696] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 01/11/2021] [Accepted: 02/04/2021] [Indexed: 05/22/2023]
Abstract
It is a common practice to maintain soil fertility based on the paddy-upland rotation with green manure in the subtropical region of China. However, rare studies are known about greenhouse gas (GHG) emissions from the paddy-upland rotation with green manure incorporation. Therefore, we conducted a field experiment of two years to compared with the effect of two kinds of green manure (CV: Chinese milk vetch and OR: Oilseed rape), and two kinds of cropping system (DR: double rice system and PR: paddy-upland rotation) on greenhouse gases emissions. We have found that the annual accumulation of CH4 of Chinese milk vetch-rice-sweet potato || soybean was significantly reduced by 32.95%∼63.22% compared with other treatments, mainly because Chinese milk vetch reduced the abundance of methanogens by reducing soil C/N ratio. Meanwhile increasing soil permeability resulting from paddy-upland rotation also reduced soil CH4 emission. However, The annual accumulation of N2O of Chinese milk vetch-rice-sweet potato || soybean was increased by 17.39%∼870.11% compared with other treatments, mainly attributed to paddy-upland rotation decreased soil pH and nosZ abundance and increased nirK and nirS, thus enhancing N2O emission, meanwhile the Chinese milk vetch incorporation and its interaction with the paddy-upland rotation has greatly enhanced the contents of NO3--N and abundance of ammonia-oxidizing archaea (AOA). The area-scaled global warming potential (GWP) and the biomass-scaled greenhouse gas emissions intensity (GHGI) of Chinese milk vetch-rice-sweet potato || soybean was reduced by 19.01%∼50.69% and 5.38%∼35.77% respectively. Thereby, the Chinese milk vetch-rice-sweet potato || soybean cropping system was suitable for agricultural sustainable development.
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Affiliation(s)
- Chuan Zhong
- Research Center on Ecological Sciences, Jiangxi Agricultural University, Nanchang, 330045, China; College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ying Liu
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Hunan, 417000, China
| | - Xintong Xu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Binjuan Yang
- Research Center on Ecological Sciences, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Muhammad Aamer
- Research Center on Ecological Sciences, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Peng Zhang
- Research Center on Ecological Sciences, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Guoqin Huang
- Research Center on Ecological Sciences, Jiangxi Agricultural University, Nanchang, 330045, China.
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Liu X, Shi Y, Zhang Q, Li G. Effects of biochar on nitrification and denitrification-mediated N 2O emissions and the associated microbial community in an agricultural soil. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:6649-6663. [PMID: 33006095 DOI: 10.1007/s11356-020-10928-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/17/2020] [Indexed: 05/25/2023]
Abstract
Nitrous oxide (N2O) is a strong greenhouse gas, and it is of great significance for N2O reduction to study the effects of biochar on its production pathway. In this research, the contributions and mechanisms of biochar on autotrophic nitrification (ANF), heterotrophic nitrification (HNF), and denitrification (DF) to N2O emissions were studied by using 15N stable isotopes and high-throughput sequencing after laboratory incubation. The results showed that biochar addition at 2% (B2) significantly reduced the N2O emissions from the ANF by an average of 20.6%, while adding 5% biochar (B5) had no significant effect on the ANF. Both B2 and B5 significantly reduced the N2O emissions from the HNF by 15.7% and 13.2%, respectively, and reduced the N2O emissions from the DF by 40.9% and 11.7%, respectively. B2 enhanced the relative contribution rate of the ANF to N2O emissions by 6.3%, while B5 had little effect on it. Biochar addition significantly changed the copy numbers of the AOA and AOB, as well as the nirK, nirS, and nosZ genes, but it had no significant effect on the community composition of the AOA and had minimal effect on the AOB community. B2 significantly increased the abundance of the genus Rhodococcus of nirK type denitrifiers and had a significant effect on the relative abundance of Cupriavidus and Pseudomonas of the nosZ type denitrifiers. These results revealed that the inhibitory effects of biochar on N2O emissions from nitrification might be attributed to the direct immobilization and adsorption of inorganic N by biochar and to its promotion of the genus Rhodococcus of nirK-type denitrifiers and the genera Cupriavidus and Pseudomonas of the nosZ-type denitrifiers. The soil exchangeable NH4+-N and NO3--N concentrations were the primary factors affecting the N2O emission rates. These results help to elucidate the effects and mechanisms of biochar on N2O production pathways in agricultural soil.
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Affiliation(s)
- Xingren Liu
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Yulong Shi
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Qingwen Zhang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Guichun Li
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
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Li Z, Xia S, Zhang R, Zhang R, Chen F, Liu Y. N 2O emissions and product ratios of nitrification and denitrification are altered by K fertilizer in acidic agricultural soils. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:115065. [PMID: 32806458 DOI: 10.1016/j.envpol.2020.115065] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 06/17/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Potassium (K) fertilizer plays an important role in increasing crop yield, quality, and nitrogen use efficiency. However, little is known about its environmental impacts, such as its effects on emissions of the greenhouse gas nitrous oxide (N2O). A nitrogen-15 (15N) tracer laboratory experiment was therefore performed in an acidic agricultural soil in the suburbs of Wuhan, central China, to determine the effects of K fertilizer on N2O emissions and nitrification/denitrification product ratios under N fertilization. During 15-d incubation periods with a fixed initial N concentration (80 mg kg-1), K application increased average N2O emission rates significantly (1.6-10.8-fold) compared to the control treatment. N2O emissions derived from nitrification and denitrification both increased in K-treated soil, and denitrification contributed more to the increase; its contribution ratio rose from 32% without K fertilizer to 53% with 300 mg kg-1 of K applied. The increase in N2O emissions under K fertilization is probably due to an increase in the activity of denitrifying microorganisms and acid-resistant nitrifying microorganisms caused by higher K+ concentrations and lower soil pH. Combined treatment with potassium chloride (KCl) and N fertilizer produced lower N2O emissions than combined treatment with potassium sulfate (K2SO4) and N fertilizer during 15-d incubation periods. Our results imply that there are significant interaction effects between N fertilizers and K fertilizers on N2O emissions. In particular, combining N fertilizers with fertilizers that reduce soil acidity or contain Cl or K ions may significantly affect agricultural N2O emissions.
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Affiliation(s)
- Zhiguo Li
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Shujie Xia
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Runhua Zhang
- Wuhan Academy of Agriculture Science and Technology, Vegetable Research Institute, Wuhan, 430345, China
| | - Runqin Zhang
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Fang Chen
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Yi Liu
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, 430074, China.
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9
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Changes of Soil Microbes Related with Carbon and Nitrogen Cycling after Long-Term CO2 Enrichment in a Typical Chinese Maize Field. SUSTAINABILITY 2020. [DOI: 10.3390/su12031250] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Elevated atmospheric CO2 concentration (eCO2) has been the most important driving factor and characteristic of climate change. To clarify the effects of eCO2 on the soil microbes and on the concurrent status of soil carbon and nitrogen, an experiment was conducted in a typical summer maize field based on a 10-year mini FACE (Free Air Carbon Dioxide Enrichment) system in North China. Both rhizospheric and bulk soils were collected for measurement. The soil microbial carbon (MBC), nitrogen (MBN), and soil mineral N were measured at two stages. Characteristics of microbes were assayed for both rhizospheric soil and bulk soils at the key stage. We examined the plasmid copy numbers, diversities, and community structures of bacteria (in terms of 16s rRNA), fungi (in terms of ITS-internal transcribed spacer), ammonia oxidizing bacteria (AOB) and denitrifiers including nirK, nirS, and nosZ using the Miseq sequencing technique. Results showed that under eCO2 conditions, both MBC and MBN in rhizospheric soil were increased significantly. The quantity of ITS was increased in the eCO2 treatment compared with that in the ambient CO2 (aCO2) treatment, while the quantity of 16s rRNA in rhizospheric soil showed decrease in the rhizospheric soil in the eCO2 treatment. ECO2 changed the relative abundance of microbes in terms of compositional proportion of some orders or genera particularly in the rhizospheric soil-n particular, Chaetomium increased for ITS, Subgroups 4 and 6 increased for 16s rRNA, Nitrosospira decreased for AOB, and some genera showed increase for nirS, nirK, and nosZ. Nitrate N was the main inorganic nitrogen form at the tasseling stage and both quantities of AOB and denitrifiers, as well as the nosZ/(nirS+nirK) showed an increase under eCO2 conditions particularly in the rhizospheric soil. The Nitrosospira decreased in abundance under eCO2 conditions in the rhizospheric soil and some genera of denitrifiers also showed differences in abundance. ECO2 did not change the diversities of microbes significantly. In general, results suggested that 10 years of eCO2 did affect the active component of C and N pools (such as MBC and MBN) and both the quantities and relative abundance of microbes which are involved in carbon and nitrogen cycling, possibly due to the differences in both the quantities and component of substrate for relevant microbes in the rhizospheric soils.
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